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    <meta charset="UTF-8">
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    <title>Document</title>
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        <p>函数可以自动调用：</p>
        <p id="demo"></p>
        <script>
            (function () {
                document.getElementById("demo").innerHTML = "Hello! 我是自己调用的";
            })();
        </script>
    </div>
    <hr>
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        <p>函数可作为一个值：</p>
        <p>x = myFunction(4,3) 或 x = 12</p>
        <p>两种情况下，x 的值都为 12。</p>
        <p id="demo"></p>
        <script>
            function myFunction(a, b) {
                return a * b;
            }
            var x = myFunction(4, 3);
            document.getElementById("demo").innerHTML = x;
        </script>
    </div>
</body>

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